/*
 * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.xml.transform.dom;

import javax.xml.transform.Result;
import org.w3c.dom.Node;

/**
 * <p>Acts as a holder for a transformation result tree in the form of a Document Object Model (DOM)
 * tree.</p>
 *
 * <p>If no output DOM source is set, the transformation will create a Document node as the holder
 * for the result of the transformation, which may be retrieved with {@link #getNode()}.</p>
 *
 * @author <a href="Jeff.Suttor@Sun.com">Jeff Suttor</a>
 */
public class DOMResult implements Result {

  /**
   * <p>If {@link javax.xml.transform.TransformerFactory#getFeature}
   * returns <code>true</code> when passed this value as an argument,
   * the <code>Transformer</code> supports <code>Result</code> output of this type.</p>
   */
  public static final String FEATURE = "http://javax.xml.transform.dom.DOMResult/feature";

  /**
   * <p>Zero-argument default constructor.</p>
   *
   * <p><code>node</code>,
   * <code>siblingNode</code> and
   * <code>systemId</code>
   * will be set to <code>null</code>.</p>
   */
  public DOMResult() {
    setNode(null);
    setNextSibling(null);
    setSystemId(null);
  }

  /**
   * <p>Use a DOM node to create a new output target.</p>
   *
   * <p>In practice, the node should be
   * a {@link org.w3c.dom.Document} node,
   * a {@link org.w3c.dom.DocumentFragment} node, or
   * a {@link org.w3c.dom.Element} node.
   * In other words, a node that accepts children.</p>
   *
   * <p><code>siblingNode</code> and
   * <code>systemId</code>
   * will be set to <code>null</code>.</p>
   *
   * @param node The DOM node that will contain the result tree.
   */
  public DOMResult(Node node) {
    setNode(node);
    setNextSibling(null);
    setSystemId(null);
  }

  /**
   * <p>Use a DOM node to create a new output target with the specified System ID.<p>
   *
   * <p>In practice, the node should be
   * a {@link org.w3c.dom.Document} node,
   * a {@link org.w3c.dom.DocumentFragment} node, or
   * a {@link org.w3c.dom.Element} node.
   * In other words, a node that accepts children.</p>
   *
   * <p><code>siblingNode</code> will be set to <code>null</code>.</p>
   *
   * @param node The DOM node that will contain the result tree.
   * @param systemId The system identifier which may be used in association with this node.
   */
  public DOMResult(Node node, String systemId) {
    setNode(node);
    setNextSibling(null);
    setSystemId(systemId);
  }

  /**
   * <p>Use a DOM node to create a new output target specifying the child node where the result
   * nodes should be inserted before.</p>
   *
   * <p>In practice, <code>node</code> and <code>nextSibling</code> should be a {@link
   * org.w3c.dom.Document} node, a {@link org.w3c.dom.DocumentFragment} node, or a {@link
   * org.w3c.dom.Element} node. In other words, a node that accepts children.</p>
   *
   * <p>Use <code>nextSibling</code> to specify the child node where the result nodes should be
   * inserted before. If <code>nextSibling</code> is not a sibling of <code>node</code>, then an
   * <code>IllegalArgumentException</code> is thrown. If <code>node</code> is <code>null</code> and
   * <code>nextSibling</code> is not <code>null</code>, then an <code>IllegalArgumentException</code>
   * is thrown. If <code>nextSibling</code> is <code>null</code>, then the behavior is the same as
   * calling {@link #DOMResult(Node node)}, i.e. append the result nodes as the last child of the
   * specified <code>node</code>.</p>
   *
   * <p><code>systemId</code> will be set to <code>null</code>.</p>
   *
   * @param node The DOM node that will contain the result tree.
   * @param nextSibling The child node where the result nodes should be inserted before.
   * @throws IllegalArgumentException If <code>nextSibling</code> is not a sibling of
   * <code>node</code> or <code>node</code> is <code>null</code> and <code>nextSibling</code> is not
   * <code>null</code>.
   * @since 1.5
   */
  public DOMResult(Node node, Node nextSibling) {

    // does the corrent parent/child relationship exist?
    if (nextSibling != null) {
      // cannot be a sibling of a null node
      if (node == null) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
      }

      // nextSibling contained by node?
      if ((node.compareDocumentPosition(nextSibling) & Node.DOCUMENT_POSITION_CONTAINED_BY) == 0) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is not contained by the node.");
      }
    }

    setNode(node);
    setNextSibling(nextSibling);
    setSystemId(null);
  }

  /**
   * <p>Use a DOM node to create a new output target specifying the child node where the result
   * nodes should be inserted before and the specified System ID.</p>
   *
   * <p>In practice, <code>node</code> and <code>nextSibling</code> should be a {@link
   * org.w3c.dom.Document} node, a {@link org.w3c.dom.DocumentFragment} node, or a {@link
   * org.w3c.dom.Element} node. In other words, a node that accepts children.</p>
   *
   * <p>Use <code>nextSibling</code> to specify the child node where the result nodes should be
   * inserted before. If <code>nextSibling</code> is not a sibling of <code>node</code>, then an
   * <code>IllegalArgumentException</code> is thrown. If <code>node</code> is <code>null</code> and
   * <code>nextSibling</code> is not <code>null</code>, then an <code>IllegalArgumentException</code>
   * is thrown. If <code>nextSibling</code> is <code>null</code>, then the behavior is the same as
   * calling {@link #DOMResult(Node node, String systemId)}, i.e. append the result nodes as the
   * last child of the specified node and use the specified System ID.</p>
   *
   * @param node The DOM node that will contain the result tree.
   * @param nextSibling The child node where the result nodes should be inserted before.
   * @param systemId The system identifier which may be used in association with this node.
   * @throws IllegalArgumentException If <code>nextSibling</code> is not a sibling of
   * <code>node</code> or <code>node</code> is <code>null</code> and <code>nextSibling</code> is not
   * <code>null</code>.
   * @since 1.5
   */
  public DOMResult(Node node, Node nextSibling, String systemId) {

    // does the corrent parent/child relationship exist?
    if (nextSibling != null) {
      // cannot be a sibling of a null node
      if (node == null) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
      }

      // nextSibling contained by node?
      if ((node.compareDocumentPosition(nextSibling) & Node.DOCUMENT_POSITION_CONTAINED_BY) == 0) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is not contained by the node.");
      }
    }

    setNode(node);
    setNextSibling(nextSibling);
    setSystemId(systemId);
  }

  /**
   * <p>Set the node that will contain the result DOM tree.<p>
   *
   * <p>In practice, the node should be
   * a {@link org.w3c.dom.Document} node,
   * a {@link org.w3c.dom.DocumentFragment} node, or
   * a {@link org.w3c.dom.Element} node.
   * In other words, a node that accepts children.</p>
   *
   * <p>An <code>IllegalStateException</code> is thrown if
   * <code>nextSibling</code> is not <code>null</code> and
   * <code>node</code> is not a parent of <code>nextSibling</code>.
   * An <code>IllegalStateException</code> is thrown if <code>node</code> is <code>null</code> and
   * <code>nextSibling</code> is not <code>null</code>.</p>
   *
   * @param node The node to which the transformation will be appended.
   * @throws IllegalStateException If <code>nextSibling</code> is not <code>null</code> and
   * <code>nextSibling</code> is not a child of <code>node</code> or <code>node</code> is
   * <code>null</code> and <code>nextSibling</code> is not <code>null</code>.
   */
  public void setNode(Node node) {
    // does the corrent parent/child relationship exist?
    if (nextSibling != null) {
      // cannot be a sibling of a null node
      if (node == null) {
        throw new IllegalStateException(
            "Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
      }

      // nextSibling contained by node?
      if ((node.compareDocumentPosition(nextSibling) & Node.DOCUMENT_POSITION_CONTAINED_BY) == 0) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is not contained by the node.");
      }
    }

    this.node = node;
  }

  /**
   * <p>Get the node that will contain the result DOM tree.</p>
   *
   * <p>If no node was set via {@link #DOMResult(Node node)}, {@link #DOMResult(Node node, String
   * systeId)}, {@link #DOMResult(Node node, Node nextSibling)}, {@link #DOMResult(Node node, Node
   * nextSibling, String systemId)} or {@link #setNode(Node node)}, then the node will be set by the
   * transformation, and may be obtained from this method once the transformation is complete.
   * Calling this method before the transformation will return <code>null</code>.</p>
   *
   * @return The node to which the transformation will be appended.
   */
  public Node getNode() {
    return node;
  }

  /**
   * <p>Set the child node before which the result nodes will be inserted.</p>
   *
   * <p>Use <code>nextSibling</code> to specify the child node before which the result nodes should
   * be inserted. If <code>nextSibling</code> is not a descendant of <code>node</code>, then an
   * <code>IllegalArgumentException</code> is thrown. If <code>node</code> is <code>null</code> and
   * <code>nextSibling</code> is not <code>null</code>, then an <code>IllegalStateException</code>
   * is thrown. If <code>nextSibling</code> is <code>null</code>, then the behavior is the same as
   * calling {@link #DOMResult(Node node)}, i.e. append the result nodes as the last child of the
   * specified <code>node</code>.</p>
   *
   * @param nextSibling The child node before which the result nodes will be inserted.
   * @throws IllegalArgumentException If <code>nextSibling</code> is not a descendant of
   * <code>node</code>.
   * @throws IllegalStateException If <code>node</code> is <code>null</code> and
   * <code>nextSibling</code> is not <code>null</code>.
   * @since 1.5
   */
  public void setNextSibling(Node nextSibling) {

    // does the corrent parent/child relationship exist?
    if (nextSibling != null) {
      // cannot be a sibling of a null node
      if (node == null) {
        throw new IllegalStateException(
            "Cannot create a DOMResult when the nextSibling is contained by the \"null\" node.");
      }

      // nextSibling contained by node?
      if ((node.compareDocumentPosition(nextSibling) & Node.DOCUMENT_POSITION_CONTAINED_BY) == 0) {
        throw new IllegalArgumentException(
            "Cannot create a DOMResult when the nextSibling is not contained by the node.");
      }
    }

    this.nextSibling = nextSibling;
  }

  /**
   * <p>Get the child node before which the result nodes will be inserted.</p>
   *
   * <p>If no node was set via
   * {@link #DOMResult(Node node, Node nextSibling)},
   * {@link #DOMResult(Node node, Node nextSibling, String systemId)} or
   * {@link #setNextSibling(Node nextSibling)},
   * then <code>null</code> will be returned.</p>
   *
   * @return The child node before which the result nodes will be inserted.
   * @since 1.5
   */
  public Node getNextSibling() {
    return nextSibling;
  }

  /**
   * <p>Set the systemId that may be used in association with the node.</p>
   *
   * @param systemId The system identifier as a URI string.
   */
  public void setSystemId(String systemId) {
    this.systemId = systemId;
  }

  /**
   * <p>Get the System Identifier.</p>
   *
   * <p>If no System ID was set via
   * {@link #DOMResult(Node node, String systemId)},
   * {@link #DOMResult(Node node, Node nextSibling, String systemId)} or
   * {@link #setSystemId(String systemId)},
   * then <code>null</code> will be returned.</p>
   *
   * @return The system identifier.
   */
  public String getSystemId() {
    return systemId;
  }

  //////////////////////////////////////////////////////////////////////
  // Internal state.
  //////////////////////////////////////////////////////////////////////

  /**
   * <p>The node to which the transformation will be appended.</p>
   */
  private Node node = null;

  /**
   * <p>The child node before which the result nodes will be inserted.</p>
   *
   * @since 1.5
   */
  private Node nextSibling = null;

  /**
   * <p>The System ID that may be used in association with the node.</p>
   */
  private String systemId = null;
}
